Epicardial bridge via the coronary sinus musculatures revealed by ultra-high-definition mapping.

Mapping and ablation of perimitral flutter, a macro-reentrant tachycardia, can be sometimes challenging. We describe a case of perimitral atrial flutter following the pulmonary vein isolation in which mitral isthmus ablation failed to terminate the arrhythmia due to epicardial-endocardial breakthrough via the muscle fibers of coronary sinus. Ultra-high-definition mapping system was utilized to locate the epicardial bridge, and spot ablation of the lesion subsequently terminated the arrhythmia.

The role of prophylaxis topical antibiotics in cardiac device implantation.

BACKGROUND: Combined systemic and topical antibiotic prophylaxes are used in cardiac electronic implantable device (CEID) procedures, but very few studies have assessed prophylactic use of topical antibiotics after CEID implantation. OBJECTIVE: To evaluate the efficacy of topical antibiotic prophylaxis in the prevention of surgical site infection after CEID implantation procedures. METHODS: This was a prospective randomized, placebo-controlled, single-center, single-operator study. All patients (n = 1,008) received standard systemic antibiotic prophylaxis. Patients were randomized into four groups and received various topical prophylaxes after procedure. All patients were followed for at least 12 months. Surgical site inflammation and infection were graded based on degree of inflammation, discharge, wound culture, and blood culture. RESULT: Fifty-eight patients developed surgical site inflammation and infection. Fourteen patients had culture-positive wound infections. Among them, 13 patients had superficial wound infections with Staphylococcus species. Only one had pocket infection with Pseudomonas bacteremia. The surgical site infection rate was higher in those with longer procedural time, associated with 2.3 times more likelihood of infection (P = 0.01). Patients with an associated malignancy were associated with 3.6 times more likelihood of infection (P < 0.01). CONCLUSIONS: Careful skin preparation prior to incision is important, whereas the use of topical antibiotics after closure has not shown significant benefit. Patients with malignancy and longer procedural times are more likely to develop infection. There is a trend for less infection with cephalic approach. Systemic antibiotics with staphylococcal coverage are needed as most of the wound culture positive infections are caused by Staphylococcus species.

The Impact of Electromagnetic Interference from Charging All-electric Vehicles on Implantable Cardioverter-defibrillator Performance.

Electric vehicles (EVs) are growing in popularity and in general use. The effect of electromagnetic interference (EMI) caused by supercharging all-electric vehicles on implantable cardioverter-defibrillator (ICD) function has not been studied. The objective of this study was to determine the extent of the effect of EMI from charging Tesla all-electric vehicles (Tesla, Inc., Austin, TX, USA) on cardiac implantable electronic device function. A proof-of-concept study was performed to explore the potential effect of EMI from Tesla vehicles while charging the battery using a 220-V wall charger and a 480-V Supercharger. Tesla Model S and Model X vehicles were used for this study. We enrolled 34 patients with stable ICD function for the initial phase using the standard wall charger, followed by an additional 35 patients for the second phase using the Supercharger. Tracings were obtained at nominal and highest sensitivity settings while patients sat in the driver's seat, passenger seat, back seats, and facing the charging port. In each position, the device and the patient were monitored in real time by a certified technician for any inappropriate sensing and/or delivery of therapies. A medical magnet was also available on site. Emergency medical services and physician supervision were available at all times, and patients were contacted the following day to ensure their well-being. No device interactions were identified at both the nominal and highest sensitivity settings of each ICD during exposure to vehicle charging using a Tesla 220-V wall charger and a 480-V Supercharger at any of the five positions in and around each vehicle. Interaction was defined as oversensing, undersensing, mode switch, or upper rate tracking behavior. There was also no damage to any ICD, and no inappropriate shocks were administered to any patient. In conclusion, transvenous ICD function is not interrupted by EMI transmitted while charging Tesla vehicles using either the 220-V wall charger or the 480-V Supercharger.

Direct Current Ablation of Deep Substrate Arrhythmia.

Direct-current ablation has been reinvestigated in animal models with considerably good outcomes and safety margins. Its modified version using biphasic energy lowers the current density further, minimizing its complications. We report a first-in-human ablation of ventricular tachycardia using biphasic direct current with short-term success and no procedural complications. (Level of Difficulty: Intermediate.).

Inappropriate Defibrillator Shocks due to Mechanical Inference from an Investigational Device.

Cardiac contractility modulation (CCM) is an investigational device-based therapy to enhance ventricular contractility in systolic heart failure patients who are not candidates for cardiac resynchronization therapy (CRT) owing to the absence of wide QRS complexes or who have failed to respond on CRT. The principal mechanism is based on the stimulation of cardiac muscles by nonexcitatory electrical signals to augment the influx of calcium ions into the cardiomyocytes. The majority of patients receiving CCM therapy have concurrent implantable cardioverter defibrillators, and the manufacturer declares both devices can be used in parallel without any interactions. Nevertheless, proper lead positioning of both devices are crucial, and it is mandatory to check device-device interactions during each and every cardiac electronic implantable device-related procedure to prevent adverse outcomes.

Utility of Intracardiac Echocardiography to Diagnose Infective Endocarditis.

Infective endocarditis (IE) can lead to significant morbidity and mortality without appropriate treatment. Modified Duke Criteria are accepted by many professional societies to establish the diagnosis of IE, and cardiac imaging is one of the major diagnostic criteria. Transesophageal echocardiography is an algorithmic escalation to diagnose IE when transthoracic echo does not appreciate a positive finding. In patients with contraindications to transesophageal echocardiography, cardiac magnetic resonance imaging, cardiac computed tomography (CT), cardiac CT angiography, and fluorodeoxyglucose positron emission tomography with CT or CT angiography may be alternative diagnostic tools. However, these imaging modalities have their own limitations such as local unavailability, the presence of non-magnetic resonance imaging compatible implants, or impaired renal function. Intracardiac echocardiography could be a considerable alternative under those circumstances.

Air Entrapment Causing Inappropriate Shock From a Subcutaneous Implantable Cardioverter Defibrillator.

Subcutaneous implantable cardioverter defibrillator (S-ICD) is an accepted alternative to conventional transvenous devices. Their efficacy in arrhythmia management is comparable to ICDs. However, those devices also have limitations such as lack of anti-tachycardia pacing capability or higher occurrence of device oversensing associated with inappropriate shocks. Air entrapment inside one or more of subcutaneous pockets has been reported as one of uncommon causes of device malfunction. It is important to recognize the wandering or drifting baseline signals during device interrogation for timely diagnosis and appropriate treatment.

A Case of Complete Heart Block With Diagnostic Challenge and Therapeutic Dilemma.

Permanent pacemaker implantation is a class I indication for all symptomatic patients with complete heart block either congenital or acquired. However, certain portions of patients with congenital complete heart block are asymptomatic. Those patients are often very young, and implanting a permanent pacemaker is not always an easy decision. A therapeutic dilemma arises when a select patient population does not meet certain criteria to gain the maximum benefits out of prophylactic pacemaker therapy. Most asymptomatic patients with congenital complete heart block will eventually become symptomatic and require pacemakers at some point in their life but the definitive answer for the ideal time to initiate pacemaker therapy in such population has not been established. We present a case of asymptomatic congenital complete heart block with junctional escape rhythm, which is capable of incrementing the heart rate with physical activity to result in a challenge in diagnosis as well as the treatment strategy.

Therapeutic Dilemma of Natural Watchman: Congenital Absence of the Left Atrial Appendage.

Congenital absence of the left atrial appendage is a rare congenital cardiac anomaly which is usually an incidental finding. We present a rare case of congenital absence of the left atrial appendage in a 77-year-old female patient with atrial fibrillation, and we will discuss the role of anticoagulation in the patient with congenital absence of the left atrial appendage based on the scientific data and theoretic background.

Cardiogenic Shock, Acute Severe Mitral Regurgitation and Complete Heart Block After Cavo-Tricuspid Isthmus Atrial Flutter Ablation.

Radiofrequency (RF) ablation is the first-line management of cavo-tricuspid isthmus dependent atrial flutter. It has been performed with 95% success rate. Adverse events are very rare. We report the first case of acute severe mitral regurgitation (MR) and complete heart block developed after successful atrial flutter ablation. A 62-year-old female with mild MR presented with palpitations. Surface electrocardiogram was suggestive of isthmus dependent atrial flutter. A duodecapolar mapping catheter showed an atrial flutter with cycle length of 280 ms. An 8 mm tipped Thermistor RF ablation catheter was placed at the cavo-tricuspid isthmus. RF energy was delivered as the catheter was dragged to the inferior vena cava. Temperature limit was 60 °C; the power output limit was 60 W. The patient converted to sinus rhythm with the first ablation line. Bi-directional block was recorded. Two additional ablation lines lasting 60 - 120 s were delivered. The patient started having chest pain and developed complete heart block with no escape rhythm. She became hypotensive and was immediately paced from the right ventricle. There were no signs of pericardial tamponade. Emergent bedside echo demonstrated severe MR with a retracted posteromedial mitral valve leaflet. She was 100% paced and EKG changes could not be assessed. Based on the sudden onset chest pain, hypotension, complete heart block and acute severe MR after ablation, the right coronary artery occlusion was suspected. She was immediately transferred to the catheterization laboratory. Coronary angiography revealed a total occlusion of the posterolateral branch from the right coronary artery. Balloon angioplasty and coronary artery stenting was performed. Complete heart block subsequently resolved. Subsequent bedside echocardiogram showed marked improvement of the MR. Patients with smaller body size have smaller hearts and more likely to have injury from RF current. Higher energy penetrates deeper and causes more tissue damage. The use of lower temperature limits (55 °C) and lower energy (60 W) for small, elderly, and female patients is encouraged.

A Case of Diffuse Alveolar Hemorrhage as a Possible Complication of Bivalirudin Therapy.

BACKGROUND Diffuse alveolar hemorrhage (DAH) is a rare but potentially fatal complication of anticoagulant or antiplatelet therapy. Bivalirudin is a specific and reversible direct thrombin inhibitor (DTI). CASE REPORT We report a case of severe DAH, possibly related to bivalirudin use, in a 61-year-old patient undergoing coronary intervention. The patient had presented with an out-of-hospital cardiac arrest due to acute ST elevation myocardial infarction (STEMI). During the coronary intervention, shortly after receiving bivalirudin, the patient started having frank bleeding from the endotracheal tube and developed hemodynamic compromise. Despite aggressive intervention and intensive care, the patient died. CONCLUSIONS At this time, to our knowledge, there have been no reports of DAH associated with the use of bivalirudin.

Electromagnetic Interference from Swimming Pool Generator Current Causing Inappropriate ICD Discharges.

Electromagnetic interference (EMI) includes any electromagnetic field signal that can be detected by device circuitry, with potentially serious consequences: incorrect sensing, pacing, device mode switching, and defibrillation. This is a unique case of extracardiac EMI by alternating current leakage from a submerged motor used to recycle chlorinated water, resulting in false rhythm detection and inappropriate ICD discharge. A 31-year-old female with arrhythmogenic right ventricular cardiomyopathy and Medtronic dual-chamber ICD placement presented after several inappropriate ICD shocks at the public swimming pool. Patient had never received prior shocks and device was appropriate at all regular follow-ups. Intracardiac electrograms revealed unique, high-frequency signals at exactly 120 msec suggestive of EMI from a strong external source of alternating current. Electrical artifact was incorrectly sensed as a ventricular arrhythmia which resulted in discharge. ICD parameters including sensing, pacing thresholds, and impedance were all normal suggesting against device malfunction. With device failure and intracardiac sources excluded, EMI was therefore strongly suspected. Avoidance of EMI source brought complete resolution with no further inappropriate shocks. After exclusion of intracardiac interference, device malfunction, and abnormal settings, extracardiac etiologies such as EMI must be thoughtfully considered and excluded. Elimination of inappropriate shocks is to "first, do no harm."

Absent Left Main Coronary Artery and Separate Ostia of Left Coronary System in a Patient with Holt-Oram Syndrome and Sinus Node Dysfunction.

BACKGROUND: Holt-Oram syndrome (HOS) is a rare but significant syndrome consisting of structural heart defects, conduction abnormalities, and upper extremity anomalies. It was first described in the British Heart Journal in 1960 by Mary Holt and Samuel Oram as a report of atrial septal defect, conduction disturbances, and hand malformations occurring in family members. Patients can present with heart blocks or symptoms of underlying congenital heart defects. CASE REPORT: A 41-year-old man with Holt-Oram syndrome presented with seizure-like activity and was found to have an underlying conduction disturbance. Physical exam showed bilateral atrophic upper extremities with anatomic disfiguration, and weakness of the intrinsic hand muscles. Cardiovascular exam revealed a slow heart rate with irregular rhythm. EKG showed sinus arrest with junctional escape rhythm. Cardiac catheterization revealed coronary anomalies, including absent left main coronary artery and separate ostia of the left anterior ascending and left circumflex coronary artery. Coronary arteries were patent. Following electrophysiology study, sick sinus syndrome and AV block were diagnosed, and the patient received implantation of a permanent pacemaker. CONCLUSIONS: This patient presented with a seizure-like episode attributed to hypoxia during asystole from an underlying cardiac conduction defect associated with Holt-Oram syndrome. Arrhythmias and heart blocks are seen in these patients, and conduction defects are highly associated with congenital heart defects. Holt-Oram syndrome rarely presents with coronary artery anomalies. There is no reported case of separate coronary ostia and absent left main coronary artery. Prompt diagnosis is important since anomalies in coronary and upper extremity vasculature might be challenging for invasive procedures.

Omnious T-wave inversions: Wellens' syndrome revisited.

Wellens' syndrome is characterized by T-wave changes in electrocardiogram (EKG) during pain-free period in a patient with intermittent angina chest pain. It carries significant diagnostic and prognostic value because this syndrome represents a pre-infarction stage of coronary artery disease involving proximal left anterior descending (LAD) artery, which can subsequently lead to extensive anterior myocardial infarctions (MIs) and even death without coronary angioplasty. Therefore, it is crucial for every physician to recognize EKG features of Wellens' syndrome in order to take appropriate immediate intervention to reduce mortality and morbidity for MI. Here, we report a case of an overweight man with 35 pack-year of smoking history who presented to Easton Hospital with intermittent pressing chest pain of 5/6 times within 10 day-period and was found to have type A Wellens' sign, which was biphasic T-waves in precordial leads V2 and V3 during pain-free period with no cardiac enzymes elevation. He was given therapeutic lovenox and subsequently underwent coronary angioplasty and had 95-99% occlusion in proximal LAD artery. The unique feature of our case was that Wellens' type B EKG changes were seen after reduction of stenosis with LAD artery stent, which was likely explained by the reperfusion of the ischemic myocardium. Therefore, it is important for physicians to recognize EKG features of Wellens' syndrome in order to take appropriate therapy to reducing mortality and morbidity form impending MI.

Not all ST-segment changes are myocardial injury: hypercalcaemia-induced ST-segment elevation.

ST-segment elevation myocardial infarction is an important, life-threatening diagnosis that requires quick diagnosis and management. We describe the case of an 83-year-old man with coronary artery disease, ischaemic cardiomyopathy with left ventricular ejection fraction of 15%, newly diagnosed multiple myeloma that had an initial ECG showing ST-segment elevation in anterior leads V1-3 and ST-segment depression in lateral leads concerning for an ST-segment elevation myocardial infarction. Troponins were negative and his calcium was 3.55 mmol/L. It was thought that the ECG changes were not indicative of cardiac ischaemia but, rather, hypercalcaemia. He was treated with fluids, diuretics and zolendronic acid, with subsequent resolution of ST-segment changes. This case demonstrates that one must consider disease other than myocardial ischaemia as the culprit of ST-segment changes if physical examination and history do not point towards myocardial injury, as unnecessary invasive revascularisation procedures have inherent risks.

Takotsubo Cardiomyopathy: A Long Term Follow-up Shows Benefit with Risk Factor Reduction.

Only sparse data was available on long-term of Takotusbo Cardiomyopathy (TC). Previous studies suggested prognosis is not necessarily benign. We report the long-term follow-up of 12 TC patients actively managed with risk factor reduction. Retrospective analysis of all patients diagnosed with TC at our hospital between 1998 and 2010. We identified 12 patients with TC among 1651 cases of emergent left heart catheterization over 12 years. Mean follow-up time was 8.3 ± 3.6 years. All were female, 87% had hypertension, 25% had history of Coronary Artery Disease (CAD), 67% had hyperlipidemia, 44% had some preceding emotional trauma, and 44% had some physical/physiological stress. Previous studies have shown that over 50% of TC patients experience future cardiac events, and 10% have a recurrence of TC. Patients were prescribed therapeutic lifestyle changes (TLC) and guideline directed medical therapy (GDMT) for aggressive risk factor reduction. TLC included diet, exercise, and cardiac rehabilitation. GDMT often included aspirin, beta-blockers, ACE-inhibitors, and statins. Follow-up echocardiograms showed recovery and maintenance of the ejection fraction. There was no cardiac mortality and no recurrences of TC. Aggressive risk factor reduction with TLC and GDMT may be effective in improving the long term outcomes of patients with TC.